Human and animal waste is the primary source of nitrogen in most wastewater discharges. In addition, certain process waters, including but not limited to industrial process waters, contain significant amounts of nitrogen compounds. Wastewater containing nitrogen compounds such as ammonia, organic nitrogen, nitrates, and nitrites that contaminate ground and surface water resources are a major concern in a world facing potable water shortages. Traditional wastewater systems do little or nothing to reduce the level of nitrogen in the released wastewater. No low-cost technology is available to directly remove ammonia from wastewater. Release of these nitrogen compounds to environmental surface water, or especially ground water, is to be avoided. In addition, the removal of nitrogen compounds from certain processes using this method may be advantageous.
Existing systems of wastewater treatment are limited to treating wastewater with bacterial digestion, oxidation, settling, and disinfection (usually using chlorination). More advanced methods, such as ozone and ultraviolet radiation, also are used to treat water and wastewater. There are no existing systems in which wastewater containing ammonia is treated to directly remove ammonia from the water. Existing systems discuss sterilization, oxidation, and biological systems but not electro-chemical technologies.
It is known to use of ozone alone to sterilize water and/or treat the organic content water. For example, U.S. Pat. No. 4,007,120 issued to Bowen, and entitled “Oxidation and ozonation chamber”, describes the use of ozone to treat and disinfect water. U.S. Pat. No. 4,053,399 issued to Donnelly, et al. and entitled “Method and system for waste treatment”, describes the use of ozone to oxidize and disinfect wastewater. U.S. Pat. No. 4,176,061 issued to Stopka, and entitled “Apparatus and method for treatment of fluid with ozone”, describes the use of ozone in the form of micro-bubbles to oxidize and to disinfect wastewater. U.S. Pat. No. 4,255,257 issued to Greiner, et al. and entitled “Process for the treatment of water”, describes the use of pressurized ozone to treat water. U.S. Pat. No. 4,545,716 issued to Boeve, and entitled “Method of producing ultrapure, pyrogen-free water”, describes the use of highly-concentrated, substantially-pure ozone to treat deionized water. U.S. Pat. No. 4,572,821 issued to Brodard, et al. and entitled “Apparatus for dissolving ozone in a fluid”, describes the use of pressurized ozone to treat water. U.S. Pat. No. 5,130,032 issued to Sartori, and entitled “Method for treating a liquid medium”, describes the use of ultrasound to disperse ozone in water and the use of ultrasound to aid in the cleanup of ozonated water. U.S. Pat. No. 5,207,993 issued to Burris, and entitled “Batch liquid purifier”, describes the use of ozone in water with recirculation of the water through the ozone injection region to purify water. U.S. Pat. No. 5,868,945 issued to Morrow, et al. and entitled “Process of treating produced water with ozone”, describes the use of ozone to treat water, containing hydrocarbons, at elevated temperatures. U.S. Pat. No. 6,006,387 issued to Cooper, et al. and entitled “Cold water ozone disinfection”, describes the use of ozone dissolved in water to disinfect mechanical assemblies. U.S. Pat. No. 6,115,862 issued to Cooper, et al. and entitled “Cold water ozone disinfection”, describes the use of ozone dissolved in water to disinfect mechanical assemblies. The disclosures of each of these references are herein incorporated by reference to the extent that they are not inconsistent with this application.
There also are disclosures relating to the use of oxidation, singly, to treat wastewater or water. For example, U.S. Pat. No. 3,992,295 issued to Box Jr., et al. and entitled “Polluted water purification”, describes a process of catalyzed oxidation. U.S. Pat. No. 4,141,829 issued to Thiel, et al. and entitled “Process for wet oxidation of organic substances”, describes a process of oxidation occurring at elevated temperatures. U.S. Pat. No. 4,604,215 issued to McCorquodale, and entitled “Wet oxidation”, describes a process of oxidation occurring at elevated temperatures. U.S. Pat. No. 4,699,720 issued to Harada, et al. and entitled “Process for treating waste water by wet oxidations”, describes a process of oxidation using catalysts. U.S. Pat. No. 4,793,919 issued to McCorquodale, and entitled “Wet oxidation system”, describes a process of oxidation occurring with mixing or stirring of the fluid. U.S. Pat. No. 5,053,142 issued to Sorensen, et al. and entitled “Method for treating polluted material”, describes a process of oxidation occurring in a fluid. U.S. Pat. No. 5,057,220 issued to Harada, et al. and entitled “Process for treating waste water”, describes a process of oxidation using catalysts. U.S. Pat. No. 5,145,587 issued to Ishii, et al. and entitled “Method for treatment of waste water”, describes a process of oxidation at elevated temperatures. U.S. Pat. No. 5,158,689 issued to Ishii, et al. and entitled “Method for purification of waste water”, describes a process of oxidation at elevated temperatures.
Additionally, U.S. Pat. No. 5,370,801 issued to Sorensen, et al. and entitled “Method for treating polluted material”, describes a process of oxidation occurring in a fluid. U.S. Pat. No. 5,614,087 issued to Le, and entitled “Wet oxidation system”, describes a process of oxidation occurring in a stirred or mixed fluid. U.S. Pat. No. 5,807,484 issued to Couture, et al. and entitled “Waste water treatment”, describes a process of oxidation using trickle filters. U.S. Pat. No. 5,888,389 issued to Griffith, et al. and entitled “Apparatus for oxidizing undigested wastewater sludges”, describes a process of supercritical oxidation occurring in a fluid at elevated temperatures and pressures.
No systems exist in the field of electrolytic removal of ammonia by direct electrolysis or by high pH chemical conversion at an electrolytic electrode. Needs exist for new systems of electrolytic removal of ammonia by direct electrolysis or by high pH chemical conversion at an electrolytic electrode.